Do these in order: the base first, then four decisions
The next move for an incorporated physician is rarely exotic; it is sequencing. Most MPC problems we untangle were not caused by a bad strategy but by decisions made out of order, a spouse added to the share register before anyone read the TOSI rules, an investment account opened inside the corporation before a surplus policy existed, salary set by habit rather than arithmetic. The corporation is a machine with four dials, and the dials interact, so the sequence below exists to keep each decision from quietly undoing the one before it. Work them in order the first time; after that, the annual review only touches the dials your year actually moved.
Here is the order that works:
- First, the base. Clean books, a corporate bank account that never mixes with personal spending, the CPSO certificate of authorization kept current, and the corporate filings up to date.
- Decision one: how you pay yourself. Salary, dividends or a blend, revisited annually, not set once.
- Decision two: what happens to the surplus. The policy for everything you bill but do not spend, which is where incorporation earns or wastes its keep.
- Decision three: who else holds shares. Family can hold non-voting MPC shares, but tax law decides whether that is worth anything.
- Decision four: what stays outside the MPC. Real estate, some investments and anything the College would not authorize belong in other pockets.
The base deserves one specific warning: keep the wall between corporate and personal money absolute. Personal spending paid from the corporate account becomes a shareholder loan or a taxable benefit, and a shareholder loan that is not repaid within a year of the corporation's year-end is generally added straight to your personal income. Physicians rarely plan this; it accumulates from a card used for groceries here and a transfer there, until the year-end file contains a five-figure problem nobody decided to create. One account, one card, one clean wall.
Before working the dials, name the facts that swing all four for you: your age and retirement horizon, your household's spending relative to your billings, your spouse's income and age, whether you own or plan to own clinic real estate, how much the corporation has already retained, and how much of your income comes from sources other than OHIP. Two physicians with identical billings and different answers to those questions should be running visibly different corporations. If you have not incorporated yet and are testing the case first, start instead with should a physician incorporate in Ontario; this page assumes the MPC exists.
The MPC rulebook physicians actually trip on
An MPC is a normal Ontario corporation wrapped in College rules, and the wrapper is where practical mistakes happen. The corporation may practise medicine and do things related or ancillary to it, including temporarily investing surplus funds; it cannot run a side business the College would not recognize. Its name must include the physician's name and the words Medicine Professional Corporation. And its certificate of authorization from the CPSO must be kept current, because a lapsed certificate means the corporation is no longer authorized to practise, which is a regulatory problem no accountant can fix after the fact.
The share register is the most consequential page in the minute book. Only physicians can hold voting shares, family members, a spouse, children, parents, can hold non-voting shares, and a trust can hold shares for minor children. No holding company can appear on that register, ever, which forecloses the standard opco-holdco structure other business owners use and shapes everything in decision four below.
Fiscal housekeeping is worth doing deliberately rather than by default. A corporation can choose a non-calendar year-end, which can smooth the workload around personal tax season and create useful timing between corporate profit and personal draws. Dividends need directors' resolutions; salaries need a payroll account and source deductions remitted on schedule; and the T2 is due whether or not anyone planned anything. None of this is difficult, but all of it must actually happen, every year, on time.
Expenses follow the same discipline. The corporation properly deducts what it costs to earn practice income: CMPA-style protection and insurance, College and association dues, CME that maintains or upgrades your professional skills, clinic overhead, staff, billing-agent fees, and the business share of a vehicle where travel between sites is genuinely required. What it cannot do is absorb household spending with a professional label on it, and physician returns attract exactly that kind of review. A clean expense policy set once, then applied mechanically, costs far less than defending an aggressive one.
One honest note on expectations. Incorporation does not reduce the tax on money you spend personally; by the time a dollar reaches your household, the combined corporate and personal tax lands near what an unincorporated physician pays. The corporation's value is deferral on what you do not spend, plus flexibility in timing and form. Physicians who spend everything they bill get administration without benefit, which is why the surplus policy in decision two, not the incorporation certificate, is the real prize.
Decision one: how you pay yourself
Set compensation by working backwards from your household budget, not forwards from your billings. The amount you need personally, after tax, determines the draw; everything above it is surplus and belongs to decision two. The form of the draw is then a genuine choice: salary creates RRSP room and CPP entitlement but requires payroll and both halves of CPP contributions, while dividends skip CPP and payroll administration but build no RRSP room and no pensionable earnings.
The blend is not permanent. Early-career physicians paying down debt often draw more and defer less; established physicians with a full RRSP habit often want exactly enough salary to maximize contribution room; physicians past their early forties should price an individual pension plan, which is funded and deducted by the corporation and can shelter more than an RRSP for the same person. A year with a parental leave, a fellowship or a practice purchase should look different from the years around it, and the corporation is precisely the tool that lets it.
Two practical notes on the dividend route. First, dividends arrive with no tax withheld, so the personal tax on them is yours to set aside and remit through instalments; physicians who switch from salary to dividends without building that habit meet their first instalment reminder with a cash problem. Second, giving up CPP is not automatically a win: contributions feel like pure cost, but they buy an indexed, guaranteed lifetime pension that is expensive to replicate privately. We treat the CPP question as a real trade-off to price, not a line to eliminate.
Smoothing is the underrated feature. Personal brackets punish lumpy income, and a physician whose earnings swing, locum years, ramp-up years, reduced-hours years, can hold profit corporately in the strong years and draw it in the lean ones, paying tax at average rather than peak rates. That requires projecting the corporate and personal pictures together before the year closes, which is the practical difference between tax planning and tax filing.
We keep the full comparison, deferral arithmetic, CPP trade-offs and the situations where each form wins, at salary vs dividends for incorporated physicians. The short version: the right answer is a blend, and the right blend is a calculation, not a philosophy.
Decision two: the surplus policy, where the MPC earns its keep
Every dollar of profit you leave in the MPC was taxed at Ontario's roughly 12.2 percent combined small-business rate instead of your top personal rate, and the difference stays invested for you until you draw it out. That deferral is the entire financial case for the corporation, so the surplus needs a written policy: how much stays in, what it is invested in, and on what schedule it eventually comes out. Money without a policy drifts into whatever the corporation's investment advisor suggests, which is not the same thing.
| Where the surplus can go | Best when | Watch for |
|---|---|---|
| Invested inside the MPC | You want maximum deferral and flexible access later | Investment income taxed near 50 percent with only part refundable; a large portfolio grinds the small-business limit |
| Drawn out and invested personally | RRSP and TFSA room is unused, or balances feel cleaner personally | Personal tax now on the draw; deferral given up on every dollar |
| Individual pension plan | Age roughly 40 plus with T4 income and a long runway | Locked-in structure, actuarial and admin costs, needs salary to work |
| Corporate-owned life insurance | Permanent insurance is needed anyway and surplus is persistent | Long commitment; value depends on the policy, so model it against the boring alternative |
Two mechanics shape the inside-the-MPC option. Investment income earned by a corporation is taxed at roughly half on the way through, with a portion refundable when the corporation later pays taxable dividends, so the system claws toward neutrality but punishes money that never comes out on a schedule. And once a corporation's investment income passes $50,000 in a year, the federal small-business limit shrinks by five dollars for every additional dollar, disappearing at $150,000; Ontario chose not to mirror that clawback, which softens the blow for Ontario physicians without removing it.
Capital gains earn a structural edge worth knowing about. When the corporation realizes a capital gain, the untaxed half credits a notional account called the capital dividend account, and balances in that account can be paid to shareholders completely tax-free with the right election. Over a long accumulation, a growth-tilted corporate portfolio therefore leaks less on the way out than its interest-heavy equivalent, which is one reason asset location between your corporate, registered and personal accounts deserves an annual look rather than a default.
The endgame belongs in the policy too. In retirement the MPC simply becomes your pension: billings stop, the portfolio pays dividends on a schedule designed against your brackets, and the refundable tax comes back year by year as the dividends flow. A physician who stops practising can surrender the College authorization and carry on with the same corporation as an ordinary investment company under a new name, so nothing forces a wind-up. What the endgame punishes is dying with a large untouched corporation, which is why drawdown planning and estate planning are the same conversation.
The practical consequence: a growing MPC portfolio is not a set-and-forget account. Asset location matters, more of the tax-heavy income personally or in registered accounts, more of the deferral-friendly growth corporately, and the drawdown schedule in retirement matters even more, because the refundable tax only comes back when dividends actually flow. This is standing annual work in our Tax Planning & Advisory practice, not a one-time setup.
Decision three: the clinic's books, and the HST edges around OHIP
Physician accounting looks simple from a distance, OHIP pays, the corporation spends, and the gap is profit, but the edges are where assessments happen. OHIP-insured services are HST-exempt, which means the corporation charges no HST and recovers none of the HST it pays on rent, supplies and services; HST is a hidden cost in every invoice. The books should still be closed monthly, reconciled to your billing records, and reviewed against a short pack: billings, overhead, cash, and the corporate and personal instalments coming due.
The exempt label does not cover everything a physician earns. Medical-legal reports and independent assessments prepared for insurers or lawyers, medical directorships and administrative stipends, cosmetic procedures, and some teaching or consulting arrangements can be taxable supplies, and once taxable revenue passes the $30,000 small-supplier threshold the corporation must register and charge HST on those streams. A physician with a busy assessment sideline can cross that line without noticing, and the reassessment arrives with interest attached.
Reconciliation is the unglamorous core of physician books. OHIP remittance advices should tie to what was submitted, with rejected and adjusted claims tracked rather than absorbed, because unworked rejections are simply revenue you earned and never collected. The same goes for third-party billing: assessments invoiced, paid and outstanding should be visible monthly. A billing agent does not remove this job; someone still has to check that the agent's numbers, the bank deposits and the books all tell one story.
Clinic physicians have a second layer: the overhead arrangement. Cost-sharing groups, agency billing among colleagues and management fees paid to a clinic entity each carry different HST consequences, and papering them casually is how exempt-side physicians end up paying unrecoverable HST on money that merely moved between colleagues. If you pay overhead into or collect overhead from any shared arrangement, the agreement deserves a tax read, not just a legal one.
Staff push the books up another level: payroll accounts, source deductions, T4s, WSIB where it applies, and Ontario's Employer Health Tax once payroll clears the private-employer exemption. The day-to-day mechanics of all of this, and how we run them for physician clients, live on our physician accounting page; the point here is that the reporting exists to feed decisions one and two, not to satisfy the CRA alone.
Decision four: what stays outside the MPC
Some things do not belong in the MPC, and for physicians the list is longer than for other business owners because the holding company route is closed. Since only physicians and family members can hold MPC shares, no holdco can sit above the practice, and surplus cannot move to a sibling investment company as a tax-free intercorporate dividend the way an ordinary business owner's profit can. The workarounds are honest but different: invest inside the MPC under decision two, or pay the personal tax and build assets outside. We work through that structural question properly at should an incorporated physician have a holding company.
Clinic real estate is the clearest outside asset. A building can sit in an ordinary corporation you or your family own and lease space to the MPC at market rent, which separates the property from practice risk, opens ownership to family without College constraints, and builds equity in a structure that survives your retirement from practice. The lease must be real, market rent, actually paid, properly papered, because a related-party lease that exists only on paper fails exactly when it matters, in an audit or a financing. The same corporation can hold the building through a purchase financed on commercial terms, with rent from the MPC servicing the mortgage, which is how many physicians end up owning their clinic premises by retirement without ever writing a large cheque from personal funds.
Registered accounts stay outside by definition, and they still come first. TFSA room compounds tax-free forever and RRSP room shelters at your top rate, so for most physicians the sensible order is to fill both before leaning fully on corporate deferral, then let the MPC hold the overflow. The corporation is the biggest tax tool you own, but it is the third-best account for the first dollars, and a plan that gets the order wrong gives up easy wins to chase harder ones.
Family shares deserve sober expectations. A spouse holding non-voting MPC shares is legal; dividends to that spouse are still caught by the tax on split income rules at the top personal rate unless an exception applies, and the ownership-based exception is specifically unavailable for professional corporations. The exceptions that work in practice are a spouse over 65 receiving dividends once the physician is 65, family genuinely working twenty or more hours a week in the practice, and reasonable salaries for real work at any age. Shares issued to family without a plan for one of those doors mostly add paperwork.
Your estate plan has to know the MPC exists. The shares are an asset your will disposes of, the College's rules constrain who can hold them and for how long after death, and a corporation full of retained earnings can face two layers of tax at death, once on the deemed disposition of your shares and again as the assets come out, unless post-mortem planning is done on time. Executors have a limited window for some of the fixes, so the right moment to design this is now, while it is cheap, with your will, your shareholder documents and your accountant's file agreeing with each other.
The last thing outside the MPC is the plan itself. Physicians searching for a CPA for incorporated healthcare professionals in Ontario are usually not missing a filing; they are missing one advisor who holds the corporate books, the surplus policy, the personal return and the structure in the same hands. That is the shape of our Ongoing Financial Partnership, and for discrete moves, a real estate purchase, a reorganization, an IPP decision, we scope defined projects in writing. Either way it starts with a free 15-minute discovery call from our Mississauga office, and the first meeting's job is simple: put your facts against the four decisions and see which one is currently costing you money.
